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ThesisItem Open Access Formulation of low fat beef burger with fat replacers(Department of Livestock Products Technology, College of Veterinary and Animal Sciences,Mannuthy, 2010) Govande Premanand, Laxmanrao; KAU; George Oommen, THealth conscious meat consumers prefer low fat meat products due to increasing incidents of high fat induced diseases. Manufacturing meat products with fat replacers (FR) enable to reduce fat and to alleviate the problems with the reduction of fat in products. Therefore, the present study was undertaken with the objectives of developing a palatable and economic formulary for low fat beef burger (LFBB) with carrageenan (CG), tapioca starch (TS), pregelatinised pork skin collagen (PSC) and their blends as FR and to assess its pH, cooking characteristics, proximate composition, nutritional value, textural and organoleptic qualities and shelf life under aerobic (AP) and vacuum packaging (VP) at 0-4oC and -20oC and its cost of production. Beef burgers (BB) are formulated at two different fat levels, viz., full fat (FF) 20 per cent and low fat (LF) 5 per cent as controls. Seven formulations of LFBB with 5 per cent fat are prepared with 0.5 per cent CG, 1.5 per cent TS, 2 per cent PSC and their blends, viz., CG-TS - 0.5% CG & 1.5% TS; CG-PSC - 0.5% CG & 2.0% PSC; TS-PSC - 1.5% TS & 2.0% PSC; CG-TS-PSC - 0.5% CG, 1.5% TS & 2.0% PSC as FR. BB are prepared as per the formularies with minced lean beef trimmings, tallow, salt, spices and condiments, rusk, ice flakes and FR. They are packaged aerobically in HDPE and in vacuum in polyethylene-polyamide (PEPA) pouches. pH, cook yield (CY), cook loss (CL), fat retention percentage (FRP), moisture retention percentage (MRP), dimensional shrinkage (DS), water holding capacity (WHC), Warner-Bratzler Shear Force (WBSF), Hunter L*, a*, b* colour values, proximate and mineral composition and nutritional value, purge loss (PL), Thiobarbituric Acid Reactive Substances (TBARS) value and sensory qualities are assessed on d 0, 10, 20 and 30 of storage at 0-4oC and -20oC or till spoilage, whichever is earlier. Six trials of the experiment were conducted. Cooking reduced the acidity of all the burgers. By the addition of FR a significantly (P< 0.05) very low acid cooked LFBB could be prepared. CY of burgers with CG-TS-PSC was significantly (P< 0.05) the highest with 85.84 per cent. LFBB with blends of FR significantly (P< 0.05) increased CY and correspondingly reduced CL. The DS in LFBB with CG-TS-PSC was significantly (P< 0.05) the lowest with 13.21 per cent. Addition of blends of FR holds water and fat in LFBB and reduces DS during cooking. FRP and MRP in CG-TS-PSC formulation was significantly (P< 0.05) the highest with 97.66 and 74.36 per cent, respectively due to blends of CG, TS and PSC. The WHC of LFBB with CG-TS-PSC was 95.36 per cent and WBSF value 5.30 N comparable to FF and the burgers were significantly (P< 0.05) most succulent, juicy and tender with the addition of blends of FR compared to tougher BB without FR. According to Hunter L*, a*, b* values, LFBB with blends of FR, especially CG-TS-PSC was lighter, less reddish (more bluish) and less yellowish (more greenish) and comparable to FF burger. Fat content in the beef trimmings and PSC were < 1.76 per cent. Cooking significantly (P< 0.05) reduced moisture content with a corresponding increase in the protein, fat, carbohydrate and ash. The percentage total calorific value of LFBB ranged from 6.36 to 7.18 of the Recommended Dietary Allowance (RDA). The contribution of fat to RDA of calorific value was from 2.22 to 2.42 per cent only, which was below the recommended 30 per cent. More than one third of the daily requirement of protein is obtained from 100g of LFBB. LFBB with FR are good sources of Na, K and P but not of Ca. Blends of FR in LFBB, especially CG-TS-PSC, were more efficient in significantly (P< 0.05) reducing PL and TBARS value on storage at 0-4oC for 10 days and at -20oC for 30 days in AP and VP. TBARS values were lower than the acceptable range of 1mg malonaldehyde/kg for oxidative rancidity. The low fat content and the presence of onion containing antioxidants in the formulary would have synergistically acted with CG in reducing the TBARS. On sensory evaluation on zero day, the LFBB with CG-TS-PSC scored significantly higher (P< 0.05) values of 7.00 and above for very good appearance and colour, very intense flavour, very desirable texture, juiciness, practically nil mouth coating and very acceptable overall acceptability similar to FF burger. But saltiness was very desirable than in FF. The LFBB with CG-TS-PSC in AP and VP retained all the sensory attributes and proximate composition even on storage. The very acceptable nature of CG-TS-PSC formulation might be due to the synergistic effect of fat replacers. The LFBB with 5 per cent fat and CG (0.5%), TS (1.5%), PSC (2%) and their blends as FR are developed economically with very acceptable overall acceptability, CY, nutritional quality, reduced PL and oxidative rancidity and shelf life up to 10 days at 0-4oC and 30 days at -20oC under AP and VP. The best LFBB with overall acceptability was CG-TS-PSC followed by CG-TS, CG-PSC, TS-PSC, PSC, CG and TS. Blends of FR are better than single FR, particularly CG-TS-PSC, as they increased CY, FRP, MRP, WHC, sensory attributes and decreased pH, CL, DS, WBSF, PL and TBARS. Further investigations with production of large quantities are required for calculation of cost of production at commercial scale.ThesisItem Open Access Standardisation of thermal processing of cuttle fish nidamental glant(Department of Processing Technology, College of Fisheries, Panangad, 2007) Bikash kumar Pati; KAU; Sherief, P MCuttlefish nidamental gland is a pair of flattened glands associated with the female reproductive system in cuttlefish. The glands are exported as a frozen product under the name cuttlefish roe. The procedure for thermal processing of cuttlefish nidamental gland in brine packed in tin plate can is standardised to produce a ready- to- eat product. The standardisation process essentially involved determination of optimum blanching conditions, retorting temperature, process time, processing parameters, optimum solid- liquid ratio and process levels to produce a safe product and assessment of quality changes during storage at room temperature. Cuttlefish nidamental gland in brine was packed in tin plate cans in 65 : 35 ratio (gland : brine) and thermal processed in an overpressure retort. The optimum blanching condition was found to be 5 % brine for 5 min. The retorting temperature and process time were selected as 121.10C and 25 min, respectively. The F0 value attained by the process was found to be 11.25 min with total process time of 30.54 min. The cook value meant to achieve tenderness of product was 81.54 min. The processed product was found to be commercially sterile. The product was acceptable even after 3 months of storage at room temperature with regard to all sensory attributes like appearance, colour, odour, taste, texture and overall acceptability. There were significant variation in the salt, pH and TBA values (P<0.05). The cut- out test showed a marginal increase in solid weight. The study showed that the cuttlefish nidamental gland can be used for processing ready to eat product, which can be stored at room temperature for long periods.ThesisItem Open Access Evaluation of different protein sources in the formulated feed for macrobrachium Rosenbergii (De Man) Juveniles(Department of Aquaculture, College of Fisheries,Panangad, 1989) Anilkumar, P; KAU; Thampy, D MThe nutritional quality of five locally available sources of protein such as clam meat, squid waste, squilla shrimp head waste and silkworm pupae was evaluated in the feed for the giant freshwater prawn, macrobrachium rosenbergii, with a view to develop a feed which is cost effective. The feeds were prepared using these locally available ingredients along with groundnut oil cake, wheat bran,tapioca flour, supplevite (a commercially available vitamin- mineral mixture) and sardine oil and maize oil mixture. The protein sources tested were not found to be grossly deficient in their nutritional quality as good survival rates of over 90% were obtained when they were used as the main protein sources in the feed of juvenile prawn. Highest growth rate was obtained for clam and squid based diets, intermediate growth response with squilla and shrimp head based diets and the lowest growth among the various sources was given by silkworm pupae diet. Feed conversion efficiency was higher for clam and squid based diets, while intermediate feed efficiency was noted for squilla and shrimp head meal diets. Lowest feed efficiency was observed for silkworm pupae diet. Protein efficiency ratio showed a similar pattern. In the second experiment, substitution with carbohydrate for protein was found to be promising from an economic point of view. It was found that lowering of protein level from 35 to 30% could be achieved by increasing the carbohydrate level from 20 to 30% without affecting the growth , survival and feed efficiency. Similarly, protein level could be lowered from 30 to 25% by increasing carbohydrate by 10% from 20% level. This suggest that a 5% reduction of costly protein could be achieved by including 10% more of carbohydrate which will be able to reduce the cost of the feed with out sacrificing the nutritional quality of the formulated feed.ThesisItem Open Access Effect of phosphatic fertilizer compounds on aquatic primary production in saline water(Department of Fishery Hydrography, College of Fisheries, Panangad, 2005) Rajkumar, K R; KAU; Mrithunjayan, P SFish production in farms largely depends on the primary productivity In the water bodies. Among many factors, plant nutrient levels and their availability in absorbable forms for the plankton is the most important one contributing to primary production. The plant nutrient element, phosphorus often found to limit the production, mainly due to the behavior of phosphorus compounds to remain in unavailable form in aquatic environment. Hence it becomes imperative to supplement phosphorus in suitable chemical form to achieve better production. While the dosage is also important, the salinity of water bodies has an interactive effect. Thus species of compounds in phosphatic fertilizer is vital. In the present study, two types of phosphatic fertilizers and combination of these fertilizers with additives were tested for their effect on aquatic primary production. Synthetic fertilizer namely single superphosphate and natural phosphatic fertilizer namely rock phosphate were selected for study. Commercial grade trisodium phosphate was used as additive in combination with single superphosphate and rockphosphate in 1: 1 ratio with respect to phosphate- P. All the above four fertilizer materials were tested in brackishwater having two salinity levels, a low salinity level of approximately 10 ppt and a high salinity level of approximately 20 ppt. Each fertilizer was added in three different doses, ie, O.lppm, 0.2 ppm and 0.4 ppm of phosphate-P. A set of control with two salinity level of water and without adding fertilizer were also run. All the experiments were done in duplicate, in accordance with statistically designed 2x4x4 Factorial Completely Randomized Design. The experiments were conducted in wide mouth polythene drums having 25 litre capacity using 20 liters of water. The experiment was set up in a protected, undisturbed, elevated place and kept exposed to sun light for 30 days. Volume loss due to evaporation was compensated by adding appropriate amount of water having corresponding salinity. 140 Water samples were drawn on l " day (before the addition of fertilizer), i\ 14th and so" days and analysed for available phosphate, total phosphate, silicate, nitrite, nitrate, iron, water pH, dissolved oxygen, carbon dioxide, total alkalinity, total hardness and calcium. Productivity was assessed on 1 st day and so" day by estimating chlorophyll. The results were statistically analysed with ANOV A technique. In the experiment, maxrmum productivity in terms of chlorophyll (14.6mg/m3) was found under the treatment with single super phosphate along with additive trisodium phosphate when applied at a dose of 0.4 ppm of phosphate-P in the high saline media. For the same type of treatment in low salinity level, a little reduced value of productivity was observed (chloropyll =13.9 mg/rrr'), The next effective treatment was rock phosphate with trisodium phosphate at a concentration of 0.4 ppm of phosphate-P, here a chlorophyll concentration of 13.6mg/m3 and 12.6 mg/rrr' were obtained in high and low salinities respectively. The minimum productivity levels were observed in treatments with rock phosphate alone in all concentrations, compared to other treatments. It could be concluded from the experiments the following i) single super phosphate with a combination of trisodium phosphate was most effective compared to rock phosphate with trisodium phosphate, which could be due to the greater solubility of single super ph~sphate ii) single super phosphate was found to be more effective than rock phosphate, which could be due to the grater solubility as already explained. iii) the concentration level of 0.4 ppm of phosphate-P was found to be the most effective in enhancing the primary production compared to the lower doses tried ie, 0.1 and 0.2 ppm. iv) along with an increase in the available phosphate from the added fertilizers there was an increase in the primary production also v) salinity was found to have some effect on production, higher the salinity grater the production. This can be due to the availability of other minerals and intrinsic factors required for the synthesis of chlorophyll and biomass.ThesisItem Open Access Studies on the maturation and reproduction of pristolepis marginata jerdon under captive conditions(Department of Fishery Biology, College of Fisheries, Panangad, 2005) Nisha, Raj; KAU; Anna Mercy, T VPristolepis marginata Jerdon commonly called “Malabar catopra” or “Malabar sunfish” or “Chutichi” in the vernacular is an attractive ornamental fish belonging to the family Nandidae. This species, which is endemic to the Kerala part of Western Ghats inhabits clear and rapid streams. The species has been enlisted as vulnerable by – the Conservation Assessment and Mangement Plan Workshop (CAMP, 1998) for fresh water fishes of India held at NBFGR, Lucknow. Conservation of the endangered/vulnerable fishes cannot become successful without protection to the resources, which support the diversity and abundance. Hence Pristolepis marginata was one of the prioritized species for the development of captive breeding technology under NBFGR – NATP programme entitled “Germplasm inventory evaluation and gene banking of fresh water fishes of India”. Anna Mercy et al., (2003) developed the captive breeding technology for Pristolepis marginata. In the present study, an attempt was made to understand the maturation and reproduction of P. marginata in captivity. Captively reared fishes from the NATP project of College of Fisheries were utilized for the present study. A total of 209 fishes (12 to 149 mm) were used for the study of reproductive biology. A six-stage key was used for the classification of the maturity stages. The size at first maturity for females and females were found to be 54 mm and 72 mm SL respectively. Gross picture of distribution of ova stocks in the anterior, middle and posterior regions of the ovary remained almost the same except for the slight variation in the percentage composition of the mode. Based on the ova diameter frequency studies, P. marginata was found to be a multiple spawner, which release eggs in two or three batches. Absolute fecundity of the fishes ranged from 1102 (first time spawner) to 4965 (repeat spawner) in fishes of size range 66 to 80 mm SL. Number and size of eggs was found to be directly proportional to the size and age of the fish. Fecundity showed a positive linear relationship with the length and weight of the fish as well as to length and weight of the ovary. The reproductive organs of P. marginata were built on the usual percoid plan with paired ovaries and testis. The ovaries of P. marginata showed asynchronous development, in which oocytes at all the stages of development were present in the same ovary at the same time. During the spermatogenesis, there is a gradual decrease in size of different stages from spermatogonia to spermatozoans. Length – weight relationship values showed that the juveniles are exhibiting allometric growth pattern with ‘ b’ value equal to 2.83. Males also showed allometric growth pattern with ‘b’ value equal to 2.68. Females have shown isometric growth pattern with ‘b’ value equal to 2.94. Average relative condition factor values were higher in juvenile (1.43) due to the higher growth rate encountered during this stage of the life cycle. Males showed higher average relative condition value than females.ThesisItem Open Access Comparative study on certain aspects of the biology of Macrobrachium Equidens Equidens (Dana, 1852) and M. Equidens Pillaii Jayachandran, 1989(Department of Fishery Biology, College of Fisheries, Panangad, 1993) Anitta Sebastian, KAU; Jayachandran, K VThe aim of the present study has been to establish the taxonomic status of Macrobrachium equidens equidens (Dana, 1852) (spotted variety) and M. equidens pillaii Jayachandran, 1989 (striped variety) which co-exist in Cochin backwaters, by undertaking investigations on certain aspects of their biology. The two populations differ in colouration, length and arrangement of teeth in the rostrum, nature of carapace, telson, proportions of different podomeres and nature of pubescence of fingers of 2nd cheliped. Considerable differences in the growth patterns of the two populations also have been noticed in the characters, such as, rostrum, cephalothorax, carapace, width of carapace and ischium, merus, carpus, propodus, palm and fingers of 2nd cheliped. The meristic studies revealed that the arrangement of rostral teeth is specific for each population. Similarly these two populations differ in the length-weight relationships also. The SDS polyacrylamide gel electrophorogram showed clear difference in the number and position of bands in the two populations. Though the early part of oogenesis of the two populations showed similarity, considerable differences have been observed in the yolk deposition. The present investigation revealed that the two populations differ drastically in respect of all the characters studied and therefore are to be considered as two distinct species. The striped variety had been described as new species twice before of which the name "sulcatus” preoccupies any other name. Therefore the present investigation proposes the names for the two species as M. equidens (Dana, 1852) and M. sulcatus (Henderson & Matthai, 1910).ThesisItem Open Access Studies on certain aspect of the biology of the barracuda of Cochin region(Department of Fishery Biology, College of Fisheries, Panangad, 1992) Krishnadas, K J; KAU; Rajasekharan Nair, JA systematic redescription of the three species viz. SphyraenajelloCuv.,S.obtusata (Cuv. & Val.) andS. barracuda (Walbaum), available in the Cochin region has been done. The food and feeding habits, breeding biology, length – weight relationship and condition cycles of S. jello, the commercially most important species of the region, have been studied in detail. A total of 141 males (270 – 943 mm TL) and 64 females (322 – 770 mm TL) collected during Nov. ’88 to Oct. ’90 were subjected to various investigations like qualitative and quantitative assessment of stomach content, feeding intensity, prey – predator length relationship, feeding habits, quantification of maturity stages, size at first maturity, spawning season and spawning frequency, sex ratio, spawning potential, length – weight relationship and condition and relative condition cycles using standard methods. S. jello is found to be a typical predator and a predominant piscivore. The species mostly feeds on small pelagic and mid – water shoaling fishes like clupeids, anchovies, scads and silverbellies, occasionally consuming cephalopods. The total length of the prey rangfed from 18.68 to 31.43% of the predator length. The size at first maturity is found to be 360 mm for males and 370 mm for females (350 – 400 mm length class). The species exhibits a prolonged spawning season in the Cochin region, spanning from April – September/October with increased activity during June to September. Individuals of S.jello spawn more than once during this prolonged spawning season. Female dominance in the population was noticed during May to July coinciding with spawning activity. The absolute fecundity of recruit spawners of S. jello ranged between 82, 431 and 1, 63,533 9400 – 501 mm TL). The intensity of feeding was lower during the period of increased spawning activity and higher during post – spawning period. The length – weight relationship worked out for the species is log W = -4.2751 + 2.5848 log L, the relationship showing no significant difference between the sexes. The relative condition cycle closely followed the spawning cycle, the values being close to ‘1’. Condition factor calculated using eviscerated weight of fish provided an index of true well being of the fish.ThesisItem Open Access Effect of eyestalk ablation on androgenic gland and male secondary sexual characters in Macrobrachium Idella (Hilgendorf)(Department of Aquaculture, College of Fisheries,Panangad, 1998) Sherine Sonia, Cubelio; KAU; Thampy, D MThe present study in the prawn, Macrobrachium idella was taken up to find out morphotypic variation among the males, the endocrine basis for these variations and also to know the role if any, the eyestalk endocrines have, on the control of androgenic gland, which in turn is controlling the development of male primary and secondary sex characters. The study conducted to find the relationship between development of sex characters with that of androgenic gland conducted using 30 male prawns of different sizes has ShO\\-l1 that these sex characters are under the control of androgenic gland and have no relationship with that of the body size. Of the 30, 22 individuals were found to have a bodylength to cheliped length ratio below 1: 1.5, their androgenic gland and appendix masculina, not fully developed indicating that they are reproductively inactive. Remaining 8 individuals have a body length to cheliped length ratio above I: 1.5. They have well developed androgenic gland and appendix masculina showing that there is positive correlation between the biomass of androgenic gland and the cheliped length. An experiment conducted to find out the effect of unilateral eyestalk ablation on growth and development of primary and seconadry sexual characters as well as on the androgenic gland, had shown that destalking brings about a positive change in the development of androgenic gland and sex characters. The increase in the size of the androgenic gland and consequent hypertrophy of primary and secondary sexual characters brought about as a result of unilateral eyestalk ablation do indicate that the GlH, a hormone produced in the eyestalk has got an inhibitory effect on androgenic gland as well as on the growth of the prawn, which when removed by " destalking" , results in the enlargement of the androgenic gland and other sexual characters.ThesisItem Open Access Studies on temporal and spatial variations of circulation and hydrographic characteristics of Panangad region of the Vembanad Lake(Department of Fishery Hydrography, College of Fisheries, Panangad, 2003) Vijayakumar, C T; KAU; Varna, K KThe objective of the study was to find the seasonal and spatial variations of different hydrographical factors of the Vcmbanad Lake around Panangad region and compare the situation with that of the other parts of the lake. Salinity, temperature, current velocity and direction, dissolved oxygen, primary production and nutrients like phosphate, nitrite and nitrate were the parameters studied. For this monthly observations of these factors were made from nine stations located in and around Panangad region of Vembanad Lake. Beside this tidal cycle observations were carried out from two stations to study the tidal variation of the factors. S.T.D. meter was used to measure salinity, and temperature and a current meter for the current measurements. Water samples from surface and sub surfaces were collected with a clean bucket and a Van Dorn bottle. The estimation of dissolved oxygen, primary production and nutrients were done by standard methods. Marked seasonal fluctuation was noticed in the temperature of different stations. Annual variation showed two maxima. The temperature was minimum during southwest monsoon and maximum during pre monsoon months. In general, the vertical thermal stratification was small. The salinity exhibited marked seasonal fluctuation and generally the monsoon months recorded very low salinity values. After that there was an increase, reaching the maximum in pre monsoon months. Some vertical stratification was noticed during certain months. The Dissolved oxygen values were low during pre monsoon months and the content was more at surface than at the bottom layers. There was high seasonal fluctuation In the phosphate concentration. It showed high concentration during pre monsoon period. Generally bottom layers showed higher phosphate concentration than the surface layers. In the case of nitrite high values were observed durin 118 the monsoon and low values during dry season. Nitrate concentration also showed seasonal variation and high values were observed during the monsoon and low values during pre monsoon. The nutrient concentration was more in the inner smaller arms of the study area, in general. These inner arms were vertically homogenous also possibly due to higher mixing generated by the friction of the sides. In the tidal cycle observations it is found that salinity showed an increase during flood tide and decrease during ebb tide. At both stations considerable reduction in flood current speed was observed during post monsoon, compared to pre monsoon. During pre-rnonsoon a comparatively well mixed condition was prevailed. Post monsoon observations indicated very clear salinity stratification. This was due to the effect of freshwater discharge, which continued during this season though at reduced rate compared to monsoon season. It is found that the tidal effect on temperature was not well marked. It can be seen that different hydrographic factors of Panangad region of the Vembanad Lake exhibited much seasonal and spatial variations and the trend was in general, same to that shown by other parts of the lake.
